The other day I was thumbing through the mail in our kitchen when my nine-year-old son came home from school and asked me if he could have a Gmail account.

“Why?” I asked nonchalantly, hiding my alarm.

“Because a lot of my friends have them, and I want to e-mail with them,” he said.

“Uh-huh,” I muttered, employing my classic mom-jujitsu move of ignoring something until it goes away. “I’ll think about it,” I said, praying that the question would just vanish on a waft of warm spring air.

He’s only nine, I thought as I watched him bound up the stairs to his bedroom, and it’s already happening?

So this is how the sucking of a child down the social-media rabbit hole begins — with an innocent question that a stunned mother can’t answer. I had no idea.

What I do know, though, is how the story ends. Who doesn’t? All you have to do is read the newspaper or have coffee with a few moms to hear how tweens and teens are morphing into sleepless zombies who text, IM, and hang out on Facebook and ­YouTube all day and night with God knows who. They can’t concentrate on their homework for longer than the span between incoming texts, and are vulnerable to cyberbullying, sexting, handing personal information over to marketers, and sharing naked pictures of themselves shotgunning Bud tall boys. And it’s all there for every college admissions officer in the country to see one day — none of it deletable.

As a fortysomething mother who recently got her first smartphone and still doesn’t really know how to use it, my son’s question set off a quiet panic in me. I began contemplating a future that included all three of my kids running wild across a vast and unsupervised digital wilderness. I’m not ready, I thought.

The thing is, I’m not a half-bad parent. I’m not crushing it by Tiger Mom or Bringing Up Bébé standards, but I am raising happy, healthy kids who go to school every day, have close friends, and still like to snuggle up with their parents at night and read a good book. But when it comes to technology, I go a little dark. Why is that?

I’m no Luddite. I use my computer for work and I text, tweet, and post clever witticisms on my Facebook page. Still, my social-media life is an outer layer to the skin-and-bones one. I shed it, often gratefully, when the day is done. But I keep hearing that the social-media worlds of adolescents are so enmeshed with their real lives that they form a kind of chemical bond. So how am I supposed to guide my children through a digital realm that their brains will one day comprehend on some freakish molecular level I can only dream of? I mean, I don’t even know if a nine-year-old can have an e-mail account. Or go on Facebook. When should a kid be allowed to have his own cell phone and start texting under the dinner table? Above all, what is my role? Am I supposed to read my kids’ every e-mail, check their search histories? Just how much time and energy are we talking about here?

I must admit, I’ve detected a certain nonchalance in my generation of parents when it comes to technology. We let our babies paw our iPhones. We pop Leapsters and PSPs into our kids’ hands like flight attendants passing out bags of pretzels. We shut them up on long trips with iPod Touches and DSes, and eventually just lug the old laptop we haven’t used in a while into their room, so they can have their beloved screen time on Saturday afternoons and we can take a nap. But in doing so, are we shirking our parental responsibility to provide guidance and structure? I’m wondering: Are there any adults on this plane, and if so, could they please report to the World Wide Web? I have a few questions.

I mean, have you seen this stuff? The anorexia sites where girls can compare notes on how to avoid eating, the YouTube videos where teens ask perfect strangers to weigh in on whether or not they’re ugly, the ­multiplayer video games where thugs beat up prostitutes? Aren’t we at all concerned that the first thing our fourth-grader’s going to do when we buy him a smartphone is take it to his room and type “boobs” into the search engine? And what happens once he leaps into social media?

I realized standing there in the kitchen that my deftly executed evasive maneuver wasn’t going to work this time. There are surely wonderful things for kids to find on the Internet and in their budding social-media lives. But there’s no ignoring the risks embedded there. After emerging from the haze of indecision that followed my son’s request, I knew I couldn’t be caught flat-footed again. What I needed was a plan, a set of rules and strategies, a guide to entering the social-media vortex at the eye level of a child. I needed to make some cold, hard decisions about what I was going to do about it all — and I needed to make them soon.

My search for answers starts with a visit to Michael Rich, the director of the Center on Media and Child Health at Children’s Hospital who’s known as the “Mediatrician.” I’ve come to his office as a wanderer seeking wisdom from a sage. “Parents,” he tells me, “are more uncomfortable with the Internet Talk than the Sex Talk.” Rich, who is compact, with a flop of graying-blond hair and a playful laugh, has made a name for himself as a kind of middleman, bridging the gap between scientific research about kids and media and parents like me who want to understand it.

Rich says that many parents feel like they have their hands full just keeping their kids away from sex and drugs, never mind the Internet, which they fear they don’t understand well enough to police anyway. But it’s in this realm that today’s kids need the most guidance, he says, because they spend more time in it than anywhere else, including school and home. “If you’re not part of your kids’ media lives,” he says, “it’s just like if you were sending them off to a party every day for six or seven hours where you didn’t know the host, you didn’t know if there was alcohol or weapons or drugs or what in the house.”

That got me thinking about that time last year when I edged past the computer one Saturday morning and spied my son playing an online video game in which a battalion of tiny soldiers were spurting wide arcs of bright red blood, then keeling over. My husband and I banned the violent video games, but once our son found some nonviolent ones, we fled the scene again, reluctant to intrude on his online life. Wrong approach, Rich tells me. He’s a friendly man in his beige khakis and washed-denim button-down, but he’s leaning forward in his seat now, his eyes locked on mine, and I suddenly feel like a patient being given a dire prognosis.

“You have to go in,” he says. “If you check out, you’ve lost.”

When our kids are young, we’re the central force in their small lives — the planet to their moons. But what the tween years — with their sudden emphasis on friends, sleepover parties, and Justin Bieber — signal above all is their leaving us. Social media makes the transition faster, simpler to observe, and more fraught. The chime of a new e-mail or blaze of an incoming text is a newfangled version of the scruffy teenager showing up at the front door, except now that scruffy teenager doesn’t live up the street and you probably don’t know his parents.

Nearly three-quarters of teens who go online use some kind of social-­networking site like Facebook. What’s our place as parents in all this? I was talking about that with a friend of mine. She put me in touch with an Arlington mom who has two girls in middle school and is trying to find the balance between firmness and understanding.

“To be honest, I spent many an hour as a teenager on the phone with friends,” she tells me, “and I knew people who had to get second and third lines because no one could make a phone call in the house. There is that communication need that kids have.” But because social media complicates these natural urges, she’s been trying to slow things down. When her older daughter first asked for e-mail when she was eight or nine years old, she set her up on a kid-friendly site called ZooBuh! (“like e-mail with training wheels”), and created a list of acceptable correspondents. When her daughter outgrew that site, though, and demanded the “grownup” Gmail, the mother gave in.

And that’s when things got complicated. A kid at school started raging at her daughter and two of her friends over e-mail, using inappropriate language. The girls didn’t know how to handle it, so they and their mothers got together. “We had a conversation about how you don’t let people treat you like that, and if you receive an e-mail like that you just, blanket, don’t respond to it,” the Arlington mom tells me. “You take it offline, you make a phone call, but it does not continue through e-mail or texting.”

Now the daughter is asking for a Facebook page. Not until she’s 13, her mother tells her. That’s the age a person has to be before her personal information can be collected and sold to advertisers, according to the Children’s Online Privacy Protection Act, or COPPA, which was passed in 1998. And so that, it turns out, is the minimum age at which kids are allowed to join Facebook. But parents help their kids lie about their age all the time so they can get on early. (According to Consumer Reports, there are 7.5 million kids younger than 13 on Facebook.)

Of course, even parents who follow COPPA can’t always keep their kids off. One day the Arlington mom’s daughter came home from school and said someone else had created a Facebook page for her. Alarmed, the mother sat down at the computer and opened the page. There, for all the world to see (literally — there were no privacy settings enabled), were her daughter’s name, birthday, and the name of the boy who’d created the account — who, in a ballsy move, had listed himself as the girl’s boyfriend. “I was furious,” the mother says. “I think it’s really creepy that anyone would set up that sort of announcement to the world that they’re in a relationship with your child.” Then she lowers her voice. “So you know what I did? In a fit of annoyance, I reported it to Facebook administrators as a page that’s impersonating someone that my daughter’s not — because technically it was — and the page was taken down.”

So what does this mean for her daughter’s future on Facebook? “We talked about it this weekend,” she says. “I said that if she really wanted this thing, we would work toward her getting it. She agreed to a few things: She has to be 13, she has to bring her math grade back up to an A-, and she has to friend me.”

Research shows that this mother is right to adopt a firm stance. Sahara Byrne and Theodore Lee, from Cornell University’s Department of Communication, have found that the best
predictor for successfully protecting children from trouble online is the ease of communication between parents and kids. And who do kids have the easiest time communicating with? Authoritarian parents, Byrne and Lee found, not the permissive ones (you know, the ones who pull mom-jujitsu moves in the kitchen).

The Arlington mother’s strategy of insisting that her kids friend her on Facebook is a common one (though one father told me he would never post or comment on his son’s wall because “that’s like jumping into the flock of birds you’re observing — they’ll just fly away”). But Sherry Turkle, the renowned MIT professor, disagrees with the mom’s tactic. Turkle, who specializes in the social studies of science and technology, wrote the book (literally — it’s called Alone Together) on how technology affects us and our relationships.

“I think it’s a private place, and I think adolescents need to have a private place,” she tells me. “I am not my daughter’s friend on Facebook. I’m not her friend — I’m her mother.” She goes on: “A very wise woman once said to me, ‘You have to let a child grow up in the generation that they grow up in.’ And I think that for parents to try to get their children to not grow up appropriately in this generation is both futile and in error. And a child who feels that they can’t have privacy on Facebook will find another social-media site on which they have privacy.”

Turkle’s statement echoes an article I’d just read in which kids were turning to cell-phone apps like Instagram and Versagram to communicate because their parents didn’t understand them well enough to monitor their use. And, as if to prove Turkle’s point, a few days later a friend puts me in touch with her sister, who tells me, “I just said to my friend, ‘Hey, your daughter’s on Facebook! She’s been sending me messages!’ And she’s like, ‘Yep, that’s the politically correct page. She has another one where she and her friends are all licking their way up Astro Pop popsicles for their boyfriends to see on their profile pictures.’”